The Sonoff SNZB-04PR2 window and door sensor is an innovative solution for monitoring doors and windows in your home. Featuring advanced Zigbee 3.0 technology, this sensor enables real-time monitoring via the eWeLink app. It reliably detects whether a door or window is opened or closed and sends instant notifications to your smartphone. In addition, the sensor features tamper detection, which alerts you if anyone attempts to remove the device. Powered by two AAA batteries, the sensor guarantees a battery life of up to three years, minimising maintenance requirements. The housing is made from UV-resistant materials and has passed rigorous testing to ensure it functions reliably even under extreme conditions. The pack includes four sensors, providing a comprehensive security solution for your home. Real-time monitoring via the eWeLink app. Tamper detection for enhanced security. Operating life of up to 3 years. UV-resistant casing for durability.